Method for copolymerizing monomers of different types

ABSTRACT

1. A PROCESS FOR THE PRODUCTION OF COPOLYMERS FROM MONOMERS OF DIFFERENT TYPES BY POLYMERIZATION IN TWO SUCESSIVE STEPS, OF WHICH THE FIRST CONSISTS IN POLYMERIZING A FIRST MONOMER IN THE PRESENCE OF A COORDINATED ANIONIC CATALYST SYSTEM COMPRISING ORGANOMETALLIC COMPOUNDS OF A METAL OF THE GROUPS IA, IIA, IIIA, OR MIX: TURRES THEREOF OF MENDELEEV&#39;&#39;S PERIODIC TABLE OF ELEMENTS, ASSOCIATED WITH A TRANSITION METAL COMPOUND OF GROUPS IV TO VIII OF SAID TABLE AND THE SECOND IS A RADICAL POLYMERIZATION IN THE PRESENCE OF A CATALYST SELECTED FROM THE GROUP CONSISTING OF OXYGEN, HYDROPEROXIDES, PEROXIDES, PERSALTS AND PERACIDES AFFECTING THE NON-DEACTIVATED POLYMER FORMED IN THE FIRST STEP, AND A SECOND MONOMER WHICH IS POLYMERIZED BY FREE RADICALS WHEREIN THAT THE REACTION MEDIUM OF THE FIRST STEP CONTAINS AN AMOUNT IN THE RANGE FROM 0.01 TO 100 MOLES OF AN ADJUVANT PER MOLE OF TRANSITION METAL COMPOUND WHICH INCREASES THE PROPORTION OF THE SECOND MONOMER IN THE SECOND STEP, FIXED ON THE POLYMER OF THE FIRST STEP, THIS ADJUVANT BEING A COMPOUND MYN, IN WHICH M IS A METAL SELECTED FROM THE GRPUP CONSISTING OF BORON AND GROUP IIB OF MENDELEEV&#39;&#39;S PERIODIC TABLE OF THE ELEMENTS, N IS THE VALENCY OF M, AND Y REPRESENTS A MEMBER SELECTED FROM THE GROUP CONSISTING OF A MONOVALENT HYDROCARBYL, A HYDROGEN ATOM, AND A HALOGEN, SAID FIRST MONOMER SELECTED FROM THE GROUP CONSISTING OF OLEFINS, PHENYL-SUBSTITUTED OLEFINS, AND DIOLEFINS AND SAID SECOND MONOMER SELECTED FROM THE GROUP CONSISTING OF VINYL ACETATE, VINYL CHLORIDE, VINYLIDENE CHLORRIDE, ALKYL ACRYLATE, ALKYL METHACRYLATE, SODIUM ACRYLATE, ZINC ACRYLATE, SODIUM METHACRYLATE, ZINC METHACRYLATE, ACRYLONITRILE, METHACRYLONITRILE, ALKYLAMINOALKYL ACRYLATE, DIALKYLAMINOALKYL ACRYLATE, ALKYLAMINOALKYL METHACRYLATE, DIALKYLAMINOALKYL METHACRYLATE, VINYLPYRIDINE, VINYLPRROLIDONE, VINYL ETHER, VINYL THIOETHER, VINYLSILANE, STRENE, METHYLSTRYENE, CHLOROSTYRENE, AND BUTADIENE MONOEPOXIDE.

United States Patent 3,851,015 METHOD FOR COPOLYMERIZING MONOMERS OFDIFFERENT TYPES Elias Agouri and Philippe Mornet, Pau, Claude Parlant,

Arthez-de-Bearn, and Jacques Rideau, Pan, France, assignors to SocieteNationale des Petroles dAquitaine, Courbevois, France N0 Drawing.Continuation-impart of application Ser. No.

227,265, Feb. 17, 1972, which is a continuation of application Ser. No.851,077, Aug. 18, 1969, both now abandoned. This application Mar. 16,1973, Ser. No.

Int. Cl. C08f /00 US. Cl. 260-878 B 15 Claims ABSTRACT OF THE DISCLOSUREThe present invention describes a process of producing block copolymersfrom monomers of different types by polymerization in two successivesteps. The first step consists in polymerizing monomers of a first typeby means of coordinated anionic catalysts comprising organo-metalliccompounds of a metal of the Groups IA, IIA, IIIA, or mixtures thereof ofMendeleevs Periodic Table of Elements, associated with a transitionmetal compound of Groups IV to VIII and the second step comprisespolymerizing a second type of monomer in the presence of the polymerformed in the first step and in the presence of free radical catalysts,wherein 0.01 to 100 moles of an adjuvant per mole of transition metalcompound is added to the reaction medium of the first step and thisadjuvant consists of a compound MY in which M is selected from the groupconsisting of boron and Group IIB metals of Mendeleevs PeriodicClassification of the Elements, :1 is the valency of M, and Y representsa member selected from the group consisting of a monovalent hydrocarbylgroup, hydrogen and a halogen atom.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is acontinuation-in-part to our previous application Ser. No. 227,265, filedFeb. 17, 1972, now abandoned, which is, in turn, a continuation of ourapplication Ser. No. 851,077, filed Aug. 18, 1969, now abandoned.

BACKGROUND OF THE INVENTION One recent process consists in, first ofall, carrying out in known manner the polymerization of a monomer,especially, olefine or diolefin in the presence of an anionic catalystsystem comprising an organometallic compound of a metal of the Group I,II or III of the Periodic Table and a compound of a transition metal;thereafter, without deactivating this catalyst system, the polymer whichis obtained has added thereto a monomer which can be subjected toradical polymerization, and a radical catalyst, especially oxygen orperoxide, and the polymerization of this second type is allowed to beeffected. Such operations are described in U.S. Pat. No. 3,277,210 forthe particular case of ethylene and vinyl acetate, while as regardsother monomers, the operations are described in French Pat. No.1,531,409 and the report of J. L. Jezl, N. S. Chu and E. M. Khelghatian,entitled: Anionic Free Radical Polymers of Alphaolefins and presentedduring a congress held at San Francisco from Mar. 31 to Apr. 5, 1968(155th A.C.S. National Meeting-Industrial and Engineering Chemistry).

By applying the known procedure under normal conditions, it is foundfirstly that it is only possible to use a fairly reduced number ofmonomers which can be polymerized by radicals, and that even in thiscase, it is 3,851,015 Patented Nov. 26, 1974 essential, for obtaining atangible quantity of copolymer, to add the monomer which can besubjected to radical polymerization, to the living polymer obtained inthe first stage, before adding the radical initiator, and secondly, thatthe proportion of monomer which can be polymerized by means of radicalsis low in the copolymer which is formed. Thus, it is only possiblesuccessfully to form 1 to 2% by weight of polyacetovinyl sequences in ablock polyethylene, and a few percent of polymer of the acrylic ormethacrylic type in block propylene. Furthermore, according to the priorart, it scarcely seems possible to regulate the length of polyolefinicsequences other than by the polymerization temperature and/or possiblyby the composition and the concentration of the catalyst system; thevery practical industrial procedure, which would consist in controllingthe molecular weight of the polymer during the anionic polymerization byextending or shortening the duration of this latter would be verydifficult to apply to the known processes, because the molecular weightquickly becomes stationary in the presence of the catalysts which areused.

The present invention provides a method which avoids the aforementioneddisadvantages. It makes possible the copolymerization of all themonomers polymerizable by means of radicals and the increase as desired,even considerably if this is necessary, of the proportion of monomerfixed in the copolymer during the radical phase; thus, for example, itmakes possible the introduction of 6% or more of vinyl acetate insteadof 1 to 2% into a polyethylene, and 40% or more of methyl methacrylate,instead of a fraction of percent or a few percent, into a polyolefine.Moreover, the process according to the invention usually makes itpossible easily to regulate the length of the chains formed by anioniccatalysts in the copolymer. On the other hand, in one particularembodiment of the invention, a polymer practically free fromhomopolymers can be obtained.

The invention provides various advantages; in particular, it permits ofimproving the suitability for dyeing of different polymers byintroduction into the chain of sequences capable of chemically fixingthe dye; it is in fact possible to introduce sequences includingfunctional groups, for example, amino, carboxy or other groups. By meansof the present invention, it becomes possible to establish polymerswhich are compatible with other dissimilar polymers. The invention alsopermits of improving the adherence of polymers to various surfaces.Other useful applications have moreover been described in the literaturereferred to above.

The process according to the invention consists in introducing, into thecopolymerization medium, before and/or during the anionicpolymerization, an adjuvant which is formed by one or more compounds ofelements belonging to the group formed by boron and the metals of GroupIIB of the Periodic Table of Mendeleev; when the anionic polymerizationhas reached the desired degree, one or more monomers to be copolymerizedare added, without deactivating the coordinated anionic catalyst and inany order, with the first polymer and an appropriate radical catalyst,and the polymerization is continued in known manner.

The adjuvant according to the invention can be represented by theformula M(Y) in which M represents a metal belonging to Group IIB of thePeriodic Table of Mendeleev, or boron; n is the valency of the elementM, and Y represents one or more monovalent 'hydracarbon radicals, ahydrogen and/ or a halogen atom, particularly chlorine.

According to one particular procedure used by the new process, theadjuvant, introduced into the copolymerization medium in the stage ofcarrying out the anionic polymerization, is formed by one or moreorganic compounds of the aforementioned elements, these being compoundsin which the element is only bonded to hydrocarbon radicals.Particularly suitable for this purpose are the derivatives of zinc andcadmium of formula in which M indicates Zn or Cd, while Ra and Rh, likeor different, represent alkyl, aryl, aralkyl, alkaryl or cycloalkylgroups having up to 12 carbon atoms; by way of example, it is possibleto mention diethyl zinc, diethyl cadmium, dipropyl zinc, dibutyl zinc,diphenyl zinc, etc., these examples being in no way limitative.Compounds such as zinc, cadmium or boron halides, particularly ZnCl canalso be employed.

Each of the two operational phases which constitute the processaccording to the invention can 'be effected at a temperature from -7 8C. to 100 C. and preferably between and 80 C.; the temperature duringthe second polymerization, i.e., the radical phase, can according tocircumstances be the same as or different from that of the first anionicpolymerization.

The coordinated anionic catalyst employed in the first operational phaseare organometallic compounds of metals of the Groups IA, IIA and/or IIIAof the Periodic Table of Mendeleev, accompanied by compounds of one ormore transition metals of the Groups IV to VIII of the said Table. Thus,the operating procedure which is particularly practical according to theinvention is that in which the anionic catalyst comprises an organicderivative, or optionally a hydride of Li, Mg, Be and/or A1 with a Ti orV compound, and in which the adjuvant defined above is preferably anorgano-zinc or an organocadmium compound.

Although this adjuvant can be introduced into the medium of the firstpolymerization from the start, it is preferable to add it progressivelyduring this polymerization. It is in fact advantageous to have a certainsubstantially constant concentration of the said adjuvant throughout theanionic polymerization.

The proportion of this adjuvant to be employed depends inter alia on thepercentage of the second monomer which it is desired to obtain in thecopolymer. It is usually of the order of 0.01 to 100 moles, andpreferably 0.1 to 50 moles, per mole of transition metal compound.Consequently, in the particularly practical case in which the saidadjuvant is an R' Zn or R' Cd (R'=alkyl), the content of Zn or Cd isgenerally from 0.01 to 100 and better still from 0.1 to 50 atoms peratom of transition metal.

As regards the proportions of organometallic catalyst and of transitionmetal, these proportions are those according to the prior art.

Moreover, as regards the other factors of the anionic phase of thepolymerization, namely, the nature and proportion of solvent, thetemperature, pressure and nature of the monomer or monomers, they aresimilar to those of the prior art, as described by way of example in thepatents or in the works of Professor Karl Ziegler.

The second phase of the polymerization, in the presence of a catalystwhich generates free radicals, is also conducted in the manner known persee. As catalysts, it is possible to use oxygen, hydroperoxides such asfor example cumene hydroperoxide, paramenthane hydroperoxide, etc.,peroxides such as benzoyl peroxide, lauroyl peroxide, etc., persaltssuch as potassium persulphate, etc., peracids, etc. In certain cases,the radical catalyst system could be formed by a combination oforgano-zinc or organo-cadmium compounds with quinones, such asbenzoquinone, naphthoquinone, etc., or phenols.

Among the main monomers for the polymerization or anioniccopolymerization are to be considered the olefines or diolefines, suchas ethylene, propylene, butene, 4-methylpent-l-ene, butadiene, isoprene,etc., which are mentioned without any limitation. It is possible tocopolymerize them according to the invention with polymerizable monomersby means of radicals, such as the vinyl, vinylidene, acryl, methacryl orother monomers, taken individually or in mixtures, particularly vinylacetate, vinyl chloride, vinylidene chloride; alkyl acrylates ormethacrylates; acrylates or methacrylates of where R is hydrogen or alower alkyl, R is a lower alkyl (C to C R being an alkylene having 1 to6 carbon atoms; sodium or zinc acrylates or methacrylates, etc.,acrylonitrile or methacrylonitrile; styrene or its derivatives;vinylcarbazole, vinylpyridines, vinylpyrrolidones; vinyl ethers orthioethers, vinylsilanes; and monoexpoxdised dienes, such as butadienemonoepoxide or the like.

One particular embodiment of the invention which is very advantageousconsists in separating the first (anionic) polymer from the medium fromwhich it is obtained before bringing it into contact with the secondmonomer for the purpose of the radical copolymerization. This separationcan be effected by the suspension of the said polymer in the solvent inwhich the anionic polymerization has taken place being filtered orcentrifuged; the solvent keeping in solution the soluble fraction of theproducts present in the anionic polymerization medium and inter aliametallic compounds and soluble polymers of relatively low molecularweight, is thus eliminated.

The solid polymer which remains is preferably washed with the same or adifferent solvent, but no operation for deactivating the catalyst iscarried out.

For achieving the second operational phase, it is then possible for thepolymer as thus prepared to be once again brought into suspension infresh inert liquid or even in the second monomer itself, after which thedispersion obtained has an appropriate radical catalyst added thereto.By inert liquid, is understood any liquid which does not deactivate thefirst polymer and does not act chemically either with the latter or withthe second monomer or monomers; this liquid can thus be such as ahydrocarbon, for example, hexane, heptane, cyclohexane, benzene, etc.,or a halogenated hydrocarbon, such as chlorobenzene, and particularlythe same liquid which served as solvent during the first polymerizationphase.

By dispersing the first polymer directly in the second monomer, it ispossible by adding a radical catalyst to effect a mass copolymerizationwhich leads to products different from those when working in solution.This procedure permits copolymers to be prepared which have very strongcontents of groups of the second type, that is to say, originating fromthe radical catalyst.

It is interesting to note that the embodiment of the inventioncomprising the separation of the first polymer before the radicalpolymerization stage makes it possible to obtain a copolymer containingpractically no homopolymers.

The examples given below illustrate the invention without limiting it;actually, the new process can be applied to other materials, within thescope of the foregoing description, and to other conditions as regardstemperature and pressure used in the art.

COMPARISON TEST To 500 ml. of dry heptane, in a l-litre reactor, areadded under inert atmosphere 1 millimole (mmole) of TiCl AA (StauferChemical Co.) and 2 mmoles of triethylaluminium Al(C H Ethylene at thepressure of 1 atmosphere is injected into the reactor, brought to C.,after which the apparatus is kept at 45 C. for 1 hour, the contentsthereof being agitated at a speed of 500 rpm.

The ethylene excess is then driven off with a stream of nitrogen, thisbeing followed by introducing into the reactor a certain quantity ofradical initiator, namely, cumene hydroperoxide (Examples 1 to 23) andparamenthane hydroperoxide (Example 24), of which the concentration inmmoles is indicated in the tables setting out the results of Examples 1to 24.

The second monomer is then added to the contents of the autoclave. Thereactor, always being agitated, is heated to 40 C. or 60 C., dependingon circumstances, for 6 hours, after which the contents of the reactorare poured into a mixture of methanol and HCl; the precipitate thusformed is separated by filtration and washed several times with anappropriate solvent for eliminating the homopolymer; the residue isdried under vacuum at 40-50" C., weighed and examined. The proportion ofthe second monomer, fixed in the form of copolymer to the polyethylene,is determined by infra-red spectral analysis.

EXAMPLES 1 TO 4 Preparation of ethylene-methyl methacrylate copolymer Aswell as the 2 mmoles of Al(C H and 1 mmole of TiCl used as anioniccatalyst in the comparison test, the contents of the reactor have addedthereto 6 to 12 mmoles of diethyl zinc Zn(C H the other operatingconditions being the same; the washing solvent is acetone in Example 4;first of all the methyl methacrylate is added, followed by cumenehydroperoxide. Table I sets out the results which were found. Example 2adiffers from Example 2, in that the ethylene polymerization was effectedin the presence of hydrogen for lowering the molecular weight of thepolymer.

It can be seen that the proportion of methyl methacrylate copolymerizedwith the ethylene has been considerably increased as a result of addingdiethyl zinc to the anionic polymerization medium, that is to say, tothe first operating stage; this proportion does in fact increase from0.65% for the process according to the prior art (comparison test), to30.5% for Example 2, which is carried out under identical conditions,except for the presence of the organo-zinc compound.

The melt indices at 190 C. under 2 kg. are 0.1 for the copolymers ofExamples 1 to 4 and 1.1 for Example 2a. By comparing Examples 2 and 4,it is confirmed that the method of introducing the monomer and thehydroperoxide has little influence on the results.

The product of Example 2 was dissolved in xylene under reflux in anargon atmosphere, in the presence of the antioxidant known under thename of Ionol." The xylene solution was added dropwise to a sufficientquantity of acetone with vigorous agitation; the formed precipitate,when dried, still contained 30% of methacrylic groups, this proving thatthese latter were indeed in the copolymer form and not in thehomopolymer form in the product.

A copolymer of the type of Examples 1 to 4, containing 26% by weight ofmethyl methacrylate, was subjected to hydrolysis in acid medium and thento successive washing operations with water, aqueous methanol andfinally acetone. After the product obtained had been dried under vacuum,infra-red analysis and also elementary analysis showed the presencetherein of about 23% of methacrylic acid. This proves that themethacrylic groups were really fixed to the polyethylene.

6 'EXAMPLES 5 TO 7 Preparation of a copolymer of ethylene with vinylacetate In this series of polymerization reactions, 25 g. of vinylacetate were added each time after the first operational stage. Variablequantities of diethyl zinc were still used, the catalyst being the sameas before. The washing of the final polymer was effected by successiveextractions with acetone and benzene.

In Example 7, oxygen replaced the cumene hydroperoxide. The temperatureof the second stage was 40 C.

Although the proportions of copolymerized vinyl acetate are smaller thanthose of methyl methacrylate in the preceding examples, they are stillgreatly increased as compared with the comparison test, because of thepresence of the organo-zinc compound.

The product of Example 7 was hydrolyzed in alkali medium (NaOH, butanol,xylene). After successive washing operations with water, methanol andacetone, the copolymer was dried under vacuum. Infra-red analysis showsthat all the acetate groups have been hydrolyzed into alcohol and theacetic groups remain well-fixed to the polyethylene.

EXAMPLES 8 TO 11 Use of anionic polymer separated from itspolymerization medium Examples 8 and 9 were carried out in the same wayas Examples 1 and 2, with methyl methacrylate, except for theproportions of this latter. In Example 9a, the triethyl aluminium wasreplaced by (C H AlCl.

On the other hand, in Examples 10 and 11, the polyethylene, precipitatedduring the first operating phase in heptane, was separated before thesecond stage. For this purpose, the suspension of this polymer, obtainedafter 1 hour at 45 C. under 1 atm. of ethylene, in the presence of 1mmole of TiCl 2 mmoles of Al(C H and respectively 6 and 12 mmoles ofZn(C H was filtered in inert atmosphere, the polymer thus separated waswashed with heptane and then once again brought into suspension in afresh fraction of this latter. It is to this suspension, free fromsoluble catalyst and soluble polymers, that the cumene hydroperoxide andthe methyl methacrylate were added. The remainder of the operation wascarried out as in Examples 1 and 2, that is to say, at 40 C. for 6hours, and the copolymer was extracted, washed and dried in the sameway.

In example 11a, TiC1 was replaced by 1 mmole of less active TiCl H, butthe ethylene pressure was 5 kg./cm. in order to compensate for thisweaker catalytic activity.

In all cases, the final polymer was washed with acetone.

Table III gives the results of these examples, which were carried outwith from 6 to 12 mmoles of diethyl zinc during the first stage, that isto say, in the polymerization of the ethylene.

TABLE III Without Previous separation separation of the polyethyleneExample 8 9 9a 11 11a Zn(C2H )2, mmoles 6 12 12 6 12 12 Cmnenehydroperoxide,

mmoles 12 12 6 12 12 Methacrylate, g 39. 3 52. 3 41. 1 40. 1 56. 1 39. 2Oopolymer obtained, g 65.2 73 38 70 70. 2 83.3 Homopolymer ofmethacrylate obtained, g 2. 2 8 1 O. 3 0. 4 O. 6 Metharlirylate fixedirtr Ighe copo ymer perceu y weightnui 21. 5 33 23 18.5 25

It is apparent from these results that the previous separation of thefirst polymer, in the present case polyethylene, permits a copolymer tobe obtained of which the content of homopolymer of second type(polymethacrylate) is only 0.3 to 0.4 g. instead of 2.2 to 8 g. for theoperations directly with the suspension such as that which results fromthe anionic polymerization. On the other hand, Examples 9a and 11a showthat it is possible to replace TiCl and the alkyl aluminium by diiferentTi or Al compounds.

EXAMPLES 12 to 14 Preparation of a copolymer of ethylene withdimethylamino-ethyl methacrylate In this series of polymerizationreactions, the operation is carried out in Example 1, except for theproportions of diethyl zinc and hydroperoxide, and the methylmethacrylate is replaced in each test by g. of dimethylamino-ethylmethacrylate. The washing solvent is acetone. Table IV sets out theresults which were found.

TABLE IV Example Comparison test 12 13 14 Zn (C2H5)2, mmoles 0 6 12 12Cumene hydroperoxide, mmoles-. 12 12 12 24 Oopolymer obtained, 90 82 65Methaerylate fixed in the copolymer, percent by weight 1. 7 4. 0 5.1 8.1

The proportions of dimethylarnino-ethyl methacrylate copolymerized inExamples 12 to 14 are clearly increased as compared with the comparisonexample, because of the presence of the organo-zinc compound.

EXAMPLES 15 and 16 Etfect of the method of introducing the monomer andthe peroxide at the time of radical polymerization TABLE V Examplenumber 15 16 Z1'l(CzH5)z, 11111111110195 12 12 Hydroperoxide,millimoles. 6 6 Copolymer obtained, 33 Dimethylarnino-ethyl methacrylatfixed mer, percent by weight 7. 6 7. 2

It can be confirmed that the method of introducing the monomer and theradical initiator has no influence on the copolymers which are obtained.The quantities of homopolymers of dimethylamino-ethyl methacrylate arealmost nil.

8 EXAMPLES 17 to 19 Preparation of copolymer of ethylene with a methylmethacrylate-dimethylamino-ethyl methacrylate copolymer These tests werecarried out under conditions similar to those of Example 13, only thequantities of the two monomers, methyl methacrylate anddimethylamino-ethyl methacrylate, varying. The washing solvent wasacetone.

EXAMPLES 20-21 Preparation of copolymer of ethylene with styrene In thisseries of tests, the ethylene was polymerized at 60 C. for 1 hour in thepresence of variable quantities of diethyl zinc and the catalyst systemformed by 1 millimole of TiCl and 2 millimoles of triethyl aluminiumAl(C H The polyethylene obtained was filtered, washed and suspendedagain in heptane .30 g. of styrene and cumene hydroperoxide was thenadded and copolymerization alowed to take place at ambient temperaturefor 20 hours.

The final copolymer was washed by successive extractions of benzene andacetone.

The results obtained are set out in Table VII.

TABLE v11 Example son test 20 21 Zn(C2H:.)2. millimoles 0 2 12 Cumenehydroperoxide, mmoles... 12 6 6 Copolymer obtained. 50 41. 2 Styrenefixed in the copolymer. percent by Compari- It is seen that the quantityof styrene fixed in the copolymer increases considerably when theanionic polymerization of the ethylene is effected in the presence ofdiethyl zinc.

EXAMPLES 22-23 Copolymerization of ethylene with styrene TABLE VIIAExample number 22 22a 22b 22c 23 232.

Temperature, C 40 4O 40 40 60 60 Duration of copolymeriza hours 4 4 4 42 2 Styrene, g 30 60 150 30 150 Copolymer obtained, g 86 70 68 73Styrene fixed in the copolymer,

percent 3. 8 7. 7 13 20 2. 6 15 EXAMPLE 24 Preparation of copolymer ofethylene with vinyl chloride In this test, the ethylene polymerizationwas effected as in Example 1. The polyethylene formed was filtered,washed and suspended in heptane, in which had previously been dissolved30 g. of vinyl chloride. The radical initiator, namely, paramenthanehydroperoxide, was then added.

The radical polymerization was carried out at 40 C. for 4 hours.

The copolymer obtained was washed by successive extractions withtetrahydrofuran.

Table VIII sets out the results obtained.

TABLE VIII Comparison test Example Zn(O2H5)2, millimoles 6 Paramenthanehydroperoxide, rnmo es 6 6 Copolyrn er obtained, g 38. 29. 5

Vinyl chloride in the copolymer, percent by weight 0 3. 7

The quantity of vinyl chloride fixed in the copolymer of Example 24 issubstantial, because of the presence of the organo-zinc compound.

EXAMPLE 25 Bulk copolymerization of polyethylene with methylmethacrylate Bulk preparation of an ethylene-styrene copolymer Theoperating conditions are those of Example 22, except that the radicalpolymerization takes place without solvent, in the presence of 240 g. ofstyrene. 80 g. of copolymer are obtained, containing 27% by weight offixed styrene.

EXAMPLES 27 AND 28 Preparation of an ethylene-styrene-methylmethacrylate terpolymer Example number Zn(G2H5)z, mmoles Cumenehydroperoxide, mmole Methyl methacrylate, g Styrene, g Product obtained,g Flxed methacrylate, percent by weight Fixed styrene, percent by welghtEXAMPLE 29 Fixation of hexyl methacrylate on polyethylene The firstoperational step is that of Examples 8 to 11, with separation of theformed polyethylene. After filtration and washing operations, thispolymer has hexyl methacrylate added thereto, for the second step. Afterthis latter, the copolymer obtained is washed with acetone andchloroform.

10 The main characteristics of this example are:

Zn(C H mmoles 12 Cumene hydroperoxide, mmoles 12 Temperature of thesecond step, C 40 Duration of the second step, hours 4 Hexylmethacrylate used, g. 60.9 Weight of copolymer obtained, g. 97.8 Percentof methacrylate in the copolymer 2.9

In a comparison test, identical in all respects, except that the firstpolymerization was elfected without diethyl zinc, the product obtaineddid not contain any hexyl methacrylate.

EXAMPLE 30 Preparation of ethylene-vinylcarbazole copolymer In the firstoperational step, the ethylene was polymerized at 40 C. for 30 minutesin the presence of 6 or 12 mmoles of diethyl zinc and the catalystsystem formed by 1 mmole of V001 and 3 mmoles of (C H AlCl, in heptane.

At the end of this first polymerization, 25 g. of vinylcarbazole andoxygen are introduced into the reaction medium and the copolymerizationis allowed to proceed at ambient temperature for 16 hours. The productwas subjected to extractions with hot benzene.

The following data characterize these operations:

Com- Example parison 30 30a Diethyl zine, mmoles 0 6 12 Oxygen.mmoles 1. 5 3 6 Oopolymer obtained, g 32 32 28 Percent by weight ofvinylcarbazole fixed n the copolymer 0. 3 3. 5 5. 6

EXAMPLE 31 Preparation of an ethylene-polyacrylonitrile copolymer Thegeneral conditions being those of the comparison test described above, 1mmole of TiCl of AA quality, 2 mmoles of triethyl aluminium and 12mmoles of diethyl zinc in 500 ml. of heptane are used in the firstanionic step; the anionic polymerization lasted 1 hour at 45 C.; theethylene pressure was 0.5 kg./cm.

In a first test, the reaction medium was used as such for the secondoperational step, while in the two other tests (31a and 31b), thissecond radical step was carried out with previously separatedpolyethylene.

For carrying out the second step, 40 g. of acrylonitrile and 6 or 12mmoles of cumene hydroperoxide were added in each case, after which themedium was kept at 40 C. for 6 hours. The copolymer obtained was washedwith dimethyl formamide for 48 hours by successive extractions.

The results of these tests are below:

Number Comparison 31 1 31a 2 31b 2 ZllEtz, mmoles 0 12 12 12Hydroperoxide, mmoles 12 12 12 6 Copolymer obtained, g 40 59 47 70Polyacrylonitrile (homopolymer, g.) 1 6.2 1. 3 14. 6

Percent by weight of acrylonitrile fixed in the copolymer 0.3 8.1 17. 817 1 Without separation of the polyethylene. 2 With separation of thepolyethylene.

The copolymer of Example 31a was subjected to several extractions in aSoxhlet apparatus with xylene for 7 8 hours to eliminate thehomopolyethylene; it was then found that more than 70% of thepolyethylene chain was well fixed to the copolymer and could not beextracted. With a synthetic mixture of polyethylene with 17.8% ofpolyacrylonitrile, the same type of extraction resulted in a completeseparation of the two homopolymers.

EXAMPLE 32 Propylene-methyl methacrylate copolymer The first operationalstep, which consists in polymerizing the propylene, i carried out in 500ml. of heptane at 65 C., under a propylene pressure of 4 kg./cm. in 30minutes. The catalyst system comprises 1 mmole of TiCl of AA quality and2 mmoles of triethyl aluminium. The a'djuvant is formed by 12 mmoles ofdiethyl ZlIlC.

Without separation of the formed polypropylene, 39.5 g. of methylmethacrylate and 12 mmoles of cumene hydroperoxide are added to thereaction medium. The radical reaction is then continued for 4 hours at40 C.

A comparison test is carried out in the same way, except that thediethyl zinc is not introduced into the reaction medium.

The following results are obtained:

Comparison Example st 32 Wei ht of copolymer, g 128. 2 92. 7 Metaerylate homopolymer, g 0. 75 2. 9 Methacrylate fixed, percent by wt 119 EXAMPLE 33 Propylene-methyl methacrylate copolymer The firstoperational step is carried out in the same way as in Example 32, butthe triethyl aluminium is replaced by (C H AlCl, used at a rate of 4mmoles with 2 mmoles of TiCl the anionic polymerization lasts 60minutes.

The radical step takes place at 40 C. for 4 hours.

The copolymer for-med is extracted several times with acetone.

The following data characterize this example:

Propylene-acrylonitrile copolymer The first anionic step took placeunder a propylene pressure of 4 kg. at 65 C. in 30 minutes, with 1 mmoleof TiCl 3 mmoles of triethyl aluminium and 12 mmoles of diethyl zinc.Without previous separation of the formed polypropylene, 20 g. ofacrylonitrile and the radical catalyst were added to the medium. Thisaddition is elfecte'd in two different ways in two concurrent tests:

No. 34A, first of all the acrylonitrile and then the peroxide are added,while in No. 34B, this order of introduction is reversed.

After 6 hours of radical polymerization, the copolymer obtained iswashed several times by extraction in dimethyl formamide.

It is seen that the order in which the reactants are introduced in thesecond step does not modify the percentage of acrylonitrile fixed to thepropylene; on the contrary, it has considerable influence on theformation of acrylonitrile homopolymer.

EXAMPLE 35 Propylene-acrylonitrile-styrene terpolymer The conditions ofthe first step are: 300 ml. of heptane, 1 mmole of TiCl 3 mmoles oftriethyl aluminium and 12 mmoles of diethyl zinc, duration 10 minutes at65 C. under a propylene pressure of 4 kg./cm.

One test (35) is effected without separation of the formedpolypropylene, while in the other two tests (35a and 35b), this polymeris separated and washed before being subjected to the second radicalstep of the operation.

In the second step, first of all 20 g. of acrylonitrile, then 20 g. ofstyrene and finally the cumene hydroperoxide, in the quantity indicatedbelow, are introduced. The polymerization lasts 6 hours at 45 C.

The copolymer obtained is washed several times with dimethyl formamide.

The characteristics of this example are:

Number Comparison 35 35a 35b ZnEtz, mmoles 0 12 12 12 Hydroperoxide,mmoles. 6 12 12 6 Copolymer obtained, g 50 63 55 50 Acrylonitrile fixedin the copolymer,

percent 0.5 1. 6 4. 8 6. 1 Fixed styrene, percent 0.3 1.3 3.8 5 2EXAMPLE 36 Propylene-dimethylamino ethyl methacrylate copolymerComparison l 36a 36b Cumene hydroperoxide, mmoles 6 6 12 Oopolymerobtained, g 46 30 53 Fixed methacrylate, percent 0.5 4. 3 6. 7

1 Without ZnEtz.

The solid copolymer obtained is suspended in 100 ml. of amonosulphonated acid dye solution known under the commercial name ofBleu Dimacide Lumiere NZJL. Sulphuric acid is added until the pH is 2.5and the suspension is agitated for minutes at C. The polymer is thenremoved from the dye bath and Washed with a 5% aqueous solution ofsodium acetate; successive washing op erations are carried out withWater until the filtrate is colourless.

While the copolymer of the comparison test is only very slightly dyed,the sequential copolymers of Examples 36a and 36b show a much moreintense colouring, which is from blue to very deep blue, Extractionswith acetone and heptane under heat on these copolymers did not affectthe intensity of the colouring; on the other hand, on a syn- 13 theticmixture of polypropylene (PP) and polydimethylaminoethyl methacrylate(PDMAEMA), dyed under the same conditions, a blue colouring is obtained,which is greatly diminished after the acetone and heptane extractions.The results show that the PDMAEMA sequence remains well-fixed to the PP.

EXAMPLE 37 Ethylene-propylene acrylonitrile copolymers Comparison N 0.37

ZnEm, mmoles 8 Cumene hydroperoxide, mmoles 6 6 copolymer obtained, g 1516 Fixed acrylonitrile, percent 1 EXAMPLE 38 Ethylene-propylene-methylmethacrylate copolymer The conditions of the first step are identicalwith those of Example 37.

In the second step, 40 g. of methyl methacrylate are used at 40 C. for 3hours. The results obtained are:

Comparison N 0. 38

ZnEtz, mmoles 0 8 Cumene hydroperoxide, mmoles- 6 6 Copolymer obtained,g 17 Methacrylate fixed in the copolymer, percent by weight 0.5 7

EXAMPLE 39 Ethylene-methyl methacrylate copolymer Operations in astainless steel 10-litre reactor.The first step is effected in 5 litresof heptane, under an ethylene pressure of 0.6 kg/em. at 50 C., for 90minutes, with 10 mmoles of TiCl mmoles of EtgAl and 120 mmoles of Et Zn,used from the start, and then 180 mmoles introduced continuously.

After filtering and washing operations on the formed polyethylene, thesecond step follows at 60 C. for 2 hours: 4 litres of heptane, 120mmoles of cumene hydroperoxide and 406.3 g. of methyl methacrylate.

After extraction with acetone and chloroform, 1237 g. of copolymer with22.5% of methacrylate are then obtained.

EXAMPLE Ethylene-styrene copolymer Operation in a stainless steel10-litre reactor.The first step takes place in 5 litres of heptane,under an ethylene pressure of 0.6 kg./cm. at C. for 90 minutes, with 10mmoles of TiCl 20 mmoles of EtgA]. and 180 mmoles of Et Zn, used fromthe start, and then 180 mmoles introduced continuously.

After filtering and washing operations on the formed polyethylene, thesecond step is conducted with 2 litres of heptane, 1388 g. of styreneand 120 mmoles of cumene hydroperoxide at C. for 4 hours.

The weight of copolymer obtained is 1050 g., containing 23.5% of fixedstyrene.

14 EXAMPLE 41 Use of diphenyl zinc as. adjuvant The test is carried outunder the same conditions as in Example 4, except for the adjuvant,which here is diphenyl zinc (12 mmoles) instead of diethyl zinc:

Copolymer obtained g- Methacrylic homopolymer g 0 Methacrylate fixed inthe copolymer percent by weight.. 30

It is seen that by using the diphenyl zinc, the formation of methylmethacrylate homopolymer is completely eliminated.

EXAMPLE 42 Use of diethyl cadmium as adjuvant The conditions of thefirst step are: 1 mmole of TiCl 2 mmoles of TBA, 12 mmoles of CdEttemperature 45 C., duration 1 hour, ethylene pressure 0.5 kg./cm.heptane 500 ml.

Without separation of the polyethylene, the second step is carried out:40 g. of acrylonitrile, at 40 C. for 6 hours, 12 mmoles of cumenehydroperoxide. The results obtained are:

Copolymers obtained g 60 Acrylonitrile homopolymer g 5 Acrylonitriletfixed in the copolymer percent by weight 7 It is seen that the CdEt hasthe same eifect as the Zl'lEtz.

EXAMPLE 43 Propylene-methyl methacrylate copolymer: dipropyl zinc Thecatalyst system and adjuvant: TiCl -Et Al-dipropyl zinc additive (12mmoles).

The two operational steps are identical with those of Example 32.

The results obtained are: weight of copolymer 102 g., methacrylichomopolymer 3 g., fixed methylacrylate 17% by Weight.

It can be seen that the dipropyl zinc has the same effect as the diethylzinc.

EXAMPLE 44 ZnCl as adjuvant in the ethylene-methyl methacrylatecopolymerization To 500 ml. of dry heptane, in a l-litre reactor, areadded in an inert atmosphere 1 mmole of TiCl 4 mmoles of zinc dichlorideand 10 mmoles of triethyl aluminium. The reactor is brought to 15 C. andethylene is injected at a pressure of 1 atmosphere for 1 hour, Whilestirring at 500 rpm.

The ethylene is then driven off by a stream of nitrogen and 4 mmoles ofcumene hydroperoxide and 40 g. of methyl methacrylate are introduced.The reactor is kept at 40 C. for 6 hours. The contents are then pouredinto a methanol-HCl mixture; the polymer thus formed is washed severaltimes with acetone in order to eliminate the methacrylate homopolymer.

68 g. of copolymer are then obtained, containing 10% by weight of methylmethacrylate and 2 g. of methacrylic homopolymer.

EXAMPLE 45 Triethyl boron as adjuvant: ethylene-vinyl chloridecopolymerization To 500 ml. of dry heptane in a l-litre reactor areadded, in an inert atmosphere, 1 mmole of TiCl 2 mmoles of triethylaluminium and 6 mmoles of triethyl boron. The reactor is brought to 45C. and ethylene is injected at a pressure of 1 atmosphere for 1 hourwhile stirring at 500 rpm.

The ethylene is then driven olf by a stream of nitrogen and 6 mmoles ofcumene hydroperoxide and 40 g. of vinyl chloride are introduced. Thereactor is then kept at C. for 6 hours. The contents are then pouredinto a methanol- HCl mixture. The polymer thus formed is washed severaltimes with tetrahydrofuran.

In this way, 70 g. of a copolymer containing 20% by weight of vinylchloride are obtained.

EXAMPLE 46 The operations of Example 1 are repeated, with diethylberyllium instead of triethyl aluminium. The same results are obtained.

The copolymers according to the invention are also used as binders formixtures of corresponding homopolymers which normally are incompatible;these binders provide the compatibility of these homopolymers. Thus, inthe case of copolymers of ethylene or propylene with acryl, vinyl orstyrene compounds, this binding property becomes noticeable from acontent of 8% of acryl, vinyl or styrene compound and more especiallybeyond 15%; excellent results are obtained with copolymers of olefinewith 15 to 50% by weight of a methacrylate or acrylate, acrylonitrile orstyrene.

EXAMPLE 47 Bulk copolymer ethylene-acrylonitrile First working phase:TiCl 1 millimole; AlEt 2 millimoles; ZnEt 12 millimoles; temperature 450.; duration 1 hour; ethylene pressure 0.5 kg./cm.

After filtration and washing the product obtained, the second workingphase is: cumene hydroperoxide 12 millimoles; acrylonitrile 240 g.; 6hours at 40 C.

Copolymer obtained: 180 g.

Percent of acrylonitrile fixed, as determined after s ccessiveextractions with dimethylformamide: 53.1%.

EXAMPLES 48 TO 50 Study of the influence of concentration in TiClExample number 48 49 50 TiCl3, mmoles used 1 2 3 Copolymer obtained, g74.1 81 Homo-polymethacrylate formed g 10. 6 20. 0 20. 2 Percentmethacrylate bound in the copolymer..- 38. 8 40 It is thus seen that theconcentration of TiCl has no substantial influence on the percent ofmethacrylate bound with polyethylene; however, the amount of homopolymeris less as that concentration is lower.

EXAMPLE 51 Preparation of styrene-methyl methacrylate copolymer (A)Without special adjuvant.To 200 ml. of dry heptane, in a reactor of 500ml, 100 ml. of anhydrous distilled styrene are introduced under inertgas atmosphere. The solution obtained, while at 80 C., is added with 4millimoles TiCl AA (Staufer Chemical Co.) and 12 mmoles of triethylaluminutm Al(C H Then it is kept at 80 C. for 5 hours.

The polymer thus obtained is washed with anhydrous heptane in inertatmosphere (free from oxygen) until monomer styrene and organometallicsoluble compounds are removed.

After the last filtration of the above washing, the polymer continues tobe kept in an inert atmosphere, it is mixed with 100 ml. heptane, 40 g.methylmethacrylate and 6 mmoles cumene hydroperoxide, at 40 C., and thistemperature is maintained during 3 hours.

The material obtained is washed with a mixture methanol+HCl, it isrinsed with methanol and dried; thus, 11.3 g. of copolymer are obtainedwith contain 4.1% methylmethacrylate; the copolymer is subjected to theextraction of homopolymethylmethacrylate with acetonitrile for 24 hoursin a Soxhlet; after the extraction only 0.4% of methylmethacrylate isfound in the material.

(B) With an adjuvant according to the invention.The operations of theabove run (A) are repeated, but 6 mmoles of diethyl-zinc Zn(C H areadded to the initial solution simultaneously with the titaniumtrichloride AA. Then the amount of copolymer obtained is 30 g. insteadof 11.3 g. in the preceding example, and the copolymer contains as muchas 69% of methyl methacrylate (instead of 4.1%). After extraction withacetonitrile, as above, the proportion of methyl methacrylate remainingin the polymer is 17%. Comparison with run (A) shows that the additionof diethyl zinc to the reaction medium results in a considerableincrease of the amount of methyl methacrylate bound in the copolymerformed.

EXAMPLE 52 Producing polystyrene (C) Only with anionic catalyst.In avessel of 500 ml. there are introduced 100 ml. of heptane to which 50ml. of anhydrous distilled styrene are added in inert atmosphere. Themixture is further added with 2 mmoles of TiCl AA and 6 mmoles oftriethyl aluminum, and it is kept at C. for 5 hours. The polymer thusobtained is washed with a mixture methanol-H01, and that leaves 12.5 g.of polystyrene having a fraction of 20% which is soluble inmethyl-ethyl-ketone by refluxing in a Soxhlet during 24 hours. X-rayanalysis does not show any isotacticity in the methyl-ethyl-ketonesoluble fraction.

(D) Anionic and free radical catalysts-The run according to (C) above isrepeated, but after the 5 hours of heating at 80 C. the content of thevessel is cooled down to 40 C. and 6 mmoles of cumene hydroperoxide areadded. The mixture is then left for 3 hours.

At the end of this period, the polymer obtained is washed, as in run(C), with HCl containing methanol; the weight of washed material is 12.6g., that means substantially the same as above, and it also contains 20%of polystyrene soluble in methylethyl-ketone by refluxing in a Soxhletfor 24 hours. X-ray analysis does not reveal the presence of isotacticpolymer in the ketone soluble polymer.

The run (D) proves that no styrene molecules fixed to the initiallyformed polystyrene molecular after the introduction of cumenehydroperoxide into the reaction medium.

(E) Anionic and free radicals catalysts in the presence of an additiveaccording to the invention-Operation is carried out as in run (D), butat the start, simultaneously with the TiCl and triethyl aluminium 6mmoles of Zn(C H are added to the initial mixture. Then, after coolingto 40 0., adding the cumene hydroperoxide and letting react for 3 hours,20 g. of polymer are obtained (instead of 12.5 g. above), which contain50% (instead of 20% above) of methyl-ethyl-ketone soluble polystyrene,and the soluble fraction shows in X-ray analysis a rather strongisotacticity.

That proves the presence of diethyl zinc resulted in the fixation ofstyrene sequences, during the free radicals catalyst action (cumenehydroperoxide), onto the polystyrene formed in the first polymerizationstep (with TiCl and AlEt Now the adjuvant makes it possible to produceisotactic polystyrene.

EXAMPLE 53 To 500 ml. of dry heptane in a 1 litre flask, under inertatmosphere, 1 millimole of TiCl 2 millimoles of 17 triethylauminum, 0.5millimole of TiCl and 12 millimoles of diethylzinc are addedsuccessively.

The content of the flask is kept at 55 C. while a stream of ethylene ispassed therethrough under 1 atmosphere pressure during 30 minutes.

The polyethylene thus obtained is filtered, washed with heptane and thenresuspended in 300 ml. of heptane; to the suspension formed 40 g. ofmethyl-methacrylate and 12 millimoles of cumene hydroperoxide are added,and the mixture is kept at 40 C. for 4 hours. After that time thematerial is poured into a mixture methanol-HCI to precipitate polymer;this is separated by filtration, washed with acetone and chloroform toremove homopolymer, and dried.

Now, 80 g. of a copolymer are obtained, which contain 25% by weight ofpolymethylmethacrylate bound to polyethylene.

EXAMPLE 54 As in the preceding example, 500 ml. dry heptane are addedsuccessively with 1 mmole TiCl 4 mmoles triethyl-aluminum and 6 mmolesdiethyl-zinc. The flask is heated to and kept at 55 C.; a stream ofethylene is injected into the liquid under 0.5 atmosphere during 30minutes, while a supplemental amount of 6 mmoles diethyl-zinc isprogressively added in the course of the 30 minutes operation.

The polyethylene, thus produced, separated by filtering and washed withheptane, is suspended in 350 ml. of styrene. The suspension is addedwith 12 mmoles of cumene hydroperoxide and kept at 40 C. for 4 hours.After that time, the polymeric material formed is precipitated as above,and homopolymer is extracted therefrom with benzene; the remainder is acopolymer which contains 25% by weight of polystyrene bound topolyethylene.

EXAMPLE 55 Operation is carried out as in Example 53, but the amount ofTiCl is 0.25 mmole, TiCl is replaced by 0.03 mmole Ti(OC H,)(tetraprop-yl titanate), and the total amount of diethyl-zinc is 24mmoles, 6 of which are introduced at the start and 18 in continue duringthe polymerization of ethylene. The polymerization is carried out at 80C. during 20 minutes, the pressure of ethylene being of 4 atmospheres.On the other hand the methyl methacrylate of Example 53 is replaced by200 ml. of styrene.

After the removal of homopolymer by extraction with benzene, 156 g. ofcopolymer are obtained, 18% by weight of which are constituted ofpolystyrene combined with polyethylene.

EXAMPLE 56 Catalyst on a magnesia containing substrate The generaloperating procedure is that of Example 53, but the compound oftransition metal used is constituted by 0.8 gram of the product formedby reacting TiCl with Mg(OH)Cl, having 0.24% by weight of Ti.Triethyl-aluminum is substituted with 5 mmoles triisobutylaluminium. Thetotal amount of diethyl-zinc is now mmoles, 6 of which are introduced atthe start and 9 in continu during the polymerization of ethylene. Thepolymerization is carried out at 80 C. for 1 hour, the pressure ofethylene being 5 atmospheres. In the second polymerizationmethylmethacrylate is replaced by 200 ml. of styrene while the amount ofcumene hydroperoxide catalyst is reduced to 6 mmoles. After theextraction of homopolymer with benzene, 150 g. of styrene-ethylenecopolymer are obtained, having 18% weight content of styrene.

EXAMPLE 57 Catalyst on magnesia containing substrate Operating procedureis like that of Example 56, except that the titanium compound used isthe product of reacting TiCL, with Mg(OC H 25 mg. of it are used, whichcontain 4.2% by weight of Ti. 2 mmoles of triethyl-aluminium areemployed. As to diethyl-zinc, its total amount is 24 mmoles, 6 of whichare introduced at the start and 18 in continu in the course of thepolymerization of ethylene; this is effected at C. for 1 hour under 2atmospheres of ethylene. In the second polymerization step 12 mmoles ofcumene hydroperoxide are employed. 236 g. of copolymer having 27% byweight of bound polystyrene are obtained.

EXAMPLE 58 In an operation similar to that of Example 57, 22 mmoles oftriethyl-alurninium are used instead of the above 2 mmoles; diethyl-zincis replaced by 10 mmoles of zinc chloride (ZnCI In the secondpolymerization step the amount of cumene hydroperoxide is reduced to 6mmoles.

250 g. of copolymer are obtained, in which 27% by weight of polystyreneare bound with polyethylene.

EXAMPLE 59 Operating conditions are the same as in Example 56 exceptthat TiCl is replaced by 0.5 mmole of VCl and in the secondpolymerization 6 mmoles only of cumene. hydroperoxide are employed. Then50 g. of copolymer are produced and they contain 20% by weight ofpolystyrene fixed to polyethylene.

EXAMPLE 60 Example Millimoles 0f Diethyl-zine used Curnene hydroperoxideGrams of- Styrene added Aorylonitrile added Oopolymer obtained.-.

Weight percent of- Acrylonitrile fixed Styrene fixed EXAMPLE 61 In anoperation similar to that of Example 22(C) the amount of diethyl-zinc ischanged to 24 mmoles. Cumene hydroxide is replaced by 12 mmoles oflauroyl-peroxide. The g. of copolymer, which are then obtained, have aponderal content of 37% polystyrene fixed to polyethylene.

EXAMPLE 62 Ethylene is polymerized in conditions similar to those ofExample 1, except that operation is carried out at 60 C., and the amountof (C H Zn employed is 24 mmoles, 12 of which are introduced at thestart, while the remaining 12 mmoles are added in continu to thepolymerization medium during the whole time of reaction.

The polyethylene thus produced is filtered off, washed with heptane, andresuspended in a fraction of heptane.

To the suspension formed 12 mmoles of cumene hydroperoxide and 40 gramsof methyl-acrylate are added, and the mixture is kept at 40 C. for 4hours. A polymeric material is obtained, which is separated and treatedas described in Example 1. Now 145 g. of copolymer, having 28% by Weightof polymethylacrylate bound to polyethylene, are obtained.

1 9 EXAMPLE 63 Four mixtures of plastic materials are prepared in adouble-screw Welding extruder, the screws of which turn at 100 r.p.m.(rotations per minute). Temperature is kept at 200 C. The productobtained is then granulated and injected into a Battenfeld 10VP25 press.

Samples of each obtained pressed material are subjected to mechanicaltests the results of which are given in the following table. Thestarting plastics are designated by PMMA--polymethylmethacrylate,

PEHD-high density polyethylene,

PE-PMMA/20-copolymer according to the present application, formed ofpolyethylene on which 20% polymethacrylate were fixed.

A B O D Composition, percent:

MA 42. 5 37. 5 35 25 67. 5 37. 5 65 25 25. 0 0 50 320 480 330 360 28 3030 40 Tonsil-impact, kg. cm./cm. 65 70 65 160 Flexural strength(Dynstat), kgJmmfl. 5. 8.5 5 8 As seen the results of B and D, withcopolymers of the invention, are better than those of A and C.

On the other hand, ultrafine fihus, obtained by hot pressing 15 thickleaflets cut by means of microtome from the above materials, show, undermicroscope, heterogeneities in A and C, while B and D appear quitehomogeneous.

EXAMPLE 64 Composition, percent:

PEHD 76. 25 60 LURAN 23. 75 15 PE-PA 0 35 Tensil strength, kgJemfi- 300600 'IensiI-impact, kg. cmJcmfl. 119 123 23513) Rockwell hardness (ASTMD-785) 110.4 L

as seen a considerable increase in strength and hardness is obtained bythe use of PE-PAS; moreover samples -F are much more homogeneous than E,under microscope.

EXAMPLE 65 Mixtures G and H are prepared by the same procedure as above.PHMA designates polyhexylmethacrylate, PE-PHMA means a copolymeraccording to the invention of polyhexylmethacrylate fixed on 90%polyethylene.

Composition, percent:

PEHD 80 50 M 20 0 PIE-PHMA 0 50 Elastic limit, kgJcm. 250 200Tensil-lrnpact, kg. cmJcmfl. 550 1, 300 Resistance to tensil-cracks,hoursm Sample H shows a much better homogeneity under microscope than G,as see it has a considerably increased resistance to impact and cracks.

What is claimed is:

1. A process for the production of copolymers from monomers of differenttypes by polymerization in two successive steps, of which the firstconsists in polymeriz ing a first monomer in the presence of acoordinated anionic catalyst system comprising organometallic compoundsof a metal of the Groups IA, IIA, IIIA, or mixtures thereof ofMendeleevs Periodic Table of Elements, associated with a transitionmetal compound of Groups IV to VIII of said Table and the second is aradical polymerization in the presence of a catalyst selected from thegroup consisting of oxygen, hydroperoxides, peroxides, persalts andperacides affecting the non-deactivated polymer formed in the firststep, and a second monomer which is polymerized by free radicals whereinthat the reaction medium of the first step contains an amount in therange from 0.01 to moles of an adjuvant per mole of transition metalcompound which increases the pro portion of the second monomer in thesecond step, fixed on the polymer of the first step, this adjuvant beinga compound MY in which M is a metal selected from the group consistingof boron and Group IIB of Mendeleevs Periodic Table of the Elements, )1is the valency of M, and Y represents a member selected from the groupconsisting of a monovalent hydrocarbyl, a hydrogen atom, and a halogen,said first monomer selected from the group consisting of olefins,phenyl-substituted olefins, and diolefins and said second monomerselected from the group consisting of vinyl acetate, vinyl chloride,vinylidene chloride, alkyl acrylate, alkyl methacrylate, sodiumacrylate, zinc acrylate, sodium methacrylate, zinc methacrylate,acrylonitrile, methacrylonitrile, alkylaminoalkyl acrylate,dialkylaminoalkyl acrylate, alkylaminoalkyl methacrylate,dialkylaminoalkyl methacrylate, vinylpyridine, vinylprrolidone, vinylether, vinyl thioether, vinylsilane, styrene, methylstryene,chlorostyrene, and butadiene monoepoxide.

2. A process according to Claim 1, wherein the proportion of theadjuvant is from 0.1 to 50 moles per mole of transition metal compound.

3. A process according to Claim 1, wherein MY is of the form MR R Mbeing Zn or Cd, while R and R are like or diiferent radicals selectedfrom the group consisting of the alkyls, aryls, aralkyls, alkaryls andcycloalkyls, the members of the group having up to 12 carbon atoms.

4. A process according to Claim 1, wherein the said adjuvant is atrialkyl boron, of which the alkyl is C to C12.

5. A process according to Claim 1, wherein the adjuvant is a hydride ofZn, Cd or B.

6. A process according to Claim 1, wherein the adjuvant is a zinchalide.

7. A process according to Claim 2, wherein the organometallic compoundis an alkyl or alkyl-halo-aluminum, the transition metal titanium, theadjuvant is a dialkyl zinc and the proportion of this adjuvant is from 1to 50 zinc atoms per titanium atom.

8.. A process according to Claim 2, wherein the organometallic compoundis an alkyl-aluminum or alkyl-haloaluminum, the transition metal isvanadium, the adjuvant is a dialkyl zinc, and the proportion of thisadjuvant is from 1 to 50 zinc atoms per vanadium atom.

9. A process according to Claim 1, wherein the monomer which is capableof anionic polymerization is ethylene or propylene, while the monomer ofthe second step is vinyl acetate, vinyl chloride; vinyl carbazole; alkylacrylate or methacrylate; acrylate or methacrylate of where R ishydrogen or a lower alkyl (C to C4), R is a lower alkyl, R being analkylene having 1 to 6 carbon atoms; acrylonitrile or styrene.

10. A process according to Claim 1, wherein each of the two steps iscarried out in a solvent.

11. A process according to Claim 2, wherein said organo-metalliccompound is trialkyl-aluminum or dialkylaluminum-chloride in which thealkyl has 2 to 6 carbon atoms, while said adjuvant is diethyl-zinc.

12. A process according to Claim '1, wherein the polymer resulting fromthe first step is separated from its reaction medium before beingsubjected to the polymerization of the second step.

13. A process according to Claim 12, wherein the polymerization ofsecond step is carried out in bulk.

14. A process according to Claim 2, wherein the organometallic compoundis an alkylor alkyl-halo'alnminum, and the transition metal compound isa titanium or vanadium compound, said transition metal compound beingsupported by a substrate.

15. A process according to Claim 14, wherein the substrate is selectedfrom magnesium hydroxyhalogenides and magnesium alkoxides.

References Cited UNITED STATES PATENTS 5/1973 Schwab 260-878 B 10/1973Peyrot 260878 B 10/1966 Mirabile et a1 260-878 B 7/ 1969 Craven 260-878B 3/1972 Shimomura et al. 260-878 B 6/1973 Chu et a1. 260878 B FOREIGNPATENTS 7/1968 France 260--878 B US. CL. X.R..

1. A PROCESS FOR THE PRODUCTION OF COPOLYMERS FROM MONOMERS OF DIFFERENTTYPES BY POLYMERIZATION IN TWO SUCESSIVE STEPS, OF WHICH THE FIRSTCONSISTS IN POLYMERIZING A FIRST MONOMER IN THE PRESENCE OF ACOORDINATED ANIONIC CATALYST SYSTEM COMPRISING ORGANOMETALLIC COMPOUNDSOF A METAL OF THE GROUPS IA, IIA, IIIA, OR MIX: TURRES THEREOF OFMENDELEEV''S PERIODIC TABLE OF ELEMENTS, ASSOCIATED WITH A TRANSITIONMETAL COMPOUND OF GROUPS IV TO VIII OF SAID TABLE AND THE SECOND IS ARADICAL POLYMERIZATION IN THE PRESENCE OF A CATALYST SELECTED FROM THEGROUP CONSISTING OF OXYGEN, HYDROPEROXIDES, PEROXIDES, PERSALTS ANDPERACIDES AFFECTING THE NON-DEACTIVATED POLYMER FORMED IN THE FIRSTSTEP, AND A SECOND MONOMER WHICH IS POLYMERIZED BY FREE RADICALS WHEREINTHAT THE REACTION MEDIUM OF THE FIRST STEP CONTAINS AN AMOUNT IN THERANGE FROM 0.01 TO 100 MOLES OF AN ADJUVANT PER MOLE OF TRANSITION METALCOMPOUND WHICH INCREASES THE PROPORTION OF THE SECOND MONOMER IN THESECOND STEP, FIXED ON THE POLYMER OF THE FIRST STEP, THIS ADJUVANT BEINGA COMPOUND MYN, IN WHICH M IS A METAL SELECTED FROM THE GRPUP CONSISTINGOF BORON AND GROUP IIB OF MENDELEEV''S PERIODIC TABLE OF THE ELEMENTS, NIS THE VALENCY OF M, AND Y REPRESENTS A MEMBER SELECTED FROM THE GROUPCONSISTING OF A MONOVALENT HYDROCARBYL, A HYDROGEN ATOM, AND A HALOGEN,SAID FIRST MONOMER SELECTED FROM THE GROUP CONSISTING OF OLEFINS,PHENYL-SUBSTITUTED OLEFINS, AND DIOLEFINS AND SAID SECOND MONOMERSELECTED FROM THE GROUP CONSISTING OF VINYL ACETATE, VINYL CHLORIDE,VINYLIDENE CHLORRIDE, ALKYL ACRYLATE, ALKYL METHACRYLATE, SODIUMACRYLATE, ZINC ACRYLATE, SODIUM METHACRYLATE, ZINC METHACRYLATE,ACRYLONITRILE, METHACRYLONITRILE, ALKYLAMINOALKYL ACRYLATE,DIALKYLAMINOALKYL ACRYLATE, ALKYLAMINOALKYL METHACRYLATE,DIALKYLAMINOALKYL METHACRYLATE, VINYLPYRIDINE, VINYLPRROLIDONE, VINYLETHER, VINYL THIOETHER, VINYLSILANE, STRENE, METHYLSTRYENE,CHLOROSTYRENE, AND BUTADIENE MONOEPOXIDE.